A display screen of an electronic device, e.g., a liquid crystal display (LCD) panel, may adjust backlight level automatically according to ambient lighting conditions. Such automatic backlight adjustment may provide a display screen brightness that is adapted to the ambient light, reducing eye fatigue and providing improved viewing comfort for a user.
A light sensor may be mounted on the electronic device for measuring the ambient lighting condition. Ambient light enters into the light sensor via an opening on the electronic device. The accuracy of the measurement depends on the geometrical relationship between the ambient light sources, the opening for the light sensor, and the orientation of the device and light sensor.